解析使用lxml和請求與python

Question

最近我試圖從網頁解析HTML表使用lxml和requests。

的Python代碼運行是這樣的：

>>> from lxml to html 
>>> import requests 
>>> page = requests.get('http://www.bigpaisa.com/candlestick-stock-screener-result/nse/bearish-evening-star-candlestick-pattern') 
>>> tree = html.fromstring(page.text)' 

然後我想用lxml.xpath()函數獲取列表來解析以下重複數據塊：

<TR> 
    <TD style="font-size: 11px;"><!-- <a href="/company-technical-details/<%=sr.getExchange()%>/<%=sr.getSymbol()%>/<%=sr.getName()%>" ><%= sr.getSymbol() %></a> --> 
        AMTEKINDIA   </TD> 
    <TD style="font-size: 11px; max-width: 135px;">AMTEK INDIA LIMITED</TD> 
    <TD>    nse   </TD> 
    <TD style="min-width: 60px; max-width: 60px;">02-01-2015</TD> 
    <TD>78</TD> 
    <TD>78.3</TD> 
    <TD>72.25</TD> 
    <TD>73.9</TD> 

但未能如願得到一個錯誤，例如：

>>> symbol=tree.xpath('//TD[@style="font-size: 11px;"][@!-- [@a href="/company-t 
echnical-details/[@%=sr.getExchange()%]/[@%=sr.getSymbol()%]/[@%=sr.getName()%]" 
][@%= sr.getSymbol() %][@/a] --]/text()') 

給出Xpath評估錯誤和

>>> prices=tree.xpath('//TD/text()') 

返回沒有值的列表。

Answer 1

您感興趣的行在<table>之內，ID爲sortable。

from lxml import html 

url = 'http://www.bigpaisa.com/candlestick-stock-screener-result/nse/bearish-%20evening-star-candlestick-pattern' 
doc = html.parse(url) 

# you can use XPath to select elements... 
rows = doc.xpath("//table[@id = 'sortable']/tbody/tr") 

# or, if you prefer, use CSS selectors instead... 
rows = doc.cssselect("table#sortable tbody tr") 

for tr in rows: 
    # do something with each tr, for example 
    tds = tr.cssselect("td") 
    print tds[4].text 

請注意，根本不需要requests模塊。